C9orf72 and amyotrophic lateral sclerosis: Intriguingly, even at a young age, in vivo motor neurons in Drosophila had markedly impaired autophagosome biogenesis, late endosome trafficking, and an accumulation of static lysosomes, indicating that early disruption in the axonal autophagolysosomal pathway may be a key pathogenic event in C9orf72 ALS (142, 144).